104 GLACIOLOGY 



back of the glacier, measured in the direction of the trend of the glacier, is only 

 3 miles, and of this about l^ miles slopes down towards the Ross Barrier instead of 

 towards Glacier Tongue. This eastern half of the land cannot therefore directly 

 contribute much ice to nourish Glacier Tongue. How then can a mass of ice which 

 projects 5 miles into the sea, and has a width on the average of about half a 

 mile, and a thickness of from 400 to 800 feet, be nourished by a land surface 

 only 1 J miles in width ? 



The explanation of this remarkable phenomenon is probably to be found in the 

 following geographical structure of the country in its vicinity : Glacier Tongue is 

 to leeward of a comparatively low gap in a long peninsula. The southern end of 



Ross 



BAt>.R.IEI<. 



S^e^o/i Sfiowiny ^/aeier — • 



Cape Armilaje' 







Fig. 44 



this peninsula is from 1000 feet to as much as 1300 feet above sea-level. In a 

 northerly direction it gradually descends to a comparatively low gap opposite the 

 point of attachment of Glacier Tongue, then the land ascends somewhat rapidly 

 towards the summit of Mount Erebus, over 13,000 feet above the sea. Erebus of 

 course offers an immense obstacle to the wind currents, and the blizzard wind which 

 near Hut Point blows from about S.S.E. is deflected, as shown by the trend of the 

 sastrugi near Glacier Tongue from S.S.E. into a nearly east and west direction, 

 consequently immense streams of snow-laden air flow over the south-western slopes 

 of Mount Erebus as well as over the depression at the base of the long peninsula, 

 terminating southwards in Hut Point, and contribute largely the necessary neve for 

 the nourishment of Glacier Tongue. Some ice is also derived from the heavy snow- 

 drifts which lie on the south-west flanks of Erebus, adjacent to the shore end of the 



